Hydrolysable tannins

These astringent antimicrobial compounds are constructed of several hydroxyl-rich phenolic segments joined to a central molecule of sugar, and may occur as monomers, dimers or trimers. They are called 'hydrolyzable' because they can be easily broken down into their component sugars and phenolic moieties via acid hydrolysis. The hydrolyzable tannins are soluble in both alcohol and water. The two subgroups are the ellagitannins (based on HHDP, the precursor of ellagic acid) and the gallotannins (based on gallate units). (-Ganora)

Hydrolysable tannins are derived from simple phenolic compounds and are linked to a sugar by esterification. They can be hydrolyzed by base to produce simple acids and sugars. Consumption of tannins may lead to reduced absorption of proteins and other nutrients. When you have high levels of tannins, the tannins can bind up to the proteins. Example, eating a lot of acorns that haven’t had enough tannin removed. Packing acorns in clay removes tannins.

Non-hydrolysable tannins or condensed tannins are formed by the polymerization of flavonoids.

Inhibitory activity of flavonoids and tannins against HIV-1 protease